Paola Saccomandi, PhD1, Giuseppe Quero, MD1, Francesco Maria Di Matteo, MD2, Riccardo Fassino, MS3, Alfonso Lapergola, MD4, Ludovica Guerriero, MD1, Guido Perrone, PhD3, Alberto Vallan, PhD3, Guido Costamagna, MD1, Michele Diana, MD, PhD4, Jacques Marescaux, MD, FACS, Hon, FRCS, Hon, FJSES, Hon, FASA4. 1IHU-Institute of Image Guided Surgery, Strasbourg, France, 2Campus Bio-Medico di Roma, Roma, Italy, 3Politecnico di Torino, Department of Electronics and Telecomunications, Torino, Italy, 4IRCAD, Research Institute against Cancer of the Digestive System, Strasbourg, France
Introduction: Cholangiocarcinoma is often diagnosed at an unresectable stage. Endoscopic stent placement is generally performed to release the tumor-induced biliary obstruction. However, stents misplacement and migration, tumor tissue ingrowth and cholangitis are relatively frequent complications. Energy-based techniques (radiofrequency ablation and photodynamic therapy) have been proposed as alternatives or in addition to the stent placement, showing controversial results.
The use of laser sources in the ablation of the biliary wall has not been investigated so far.
This study aims at the evaluation of the optimal power and exposure time to achieve a controlled circumferential intraluminal laser ablation of the common bile duct (CBD).
Methods: Through a laparotomy access, the CBD of 4 pigs was exposed and a small choledocotomy was made. A confocal endomicroscopy (CE) scanning (Cellvizio) was performed through the choledocotomy, after injection of 5 ml of sodium fluorescein. The 1.2mm diameter circumferentially-emitting diode laser probe (940nm wavelength) was introduced in the CBD. Laser ablation was performed at 7W during 180s (n=2) or 360s (n=2). The power setting was predetermined on preliminary ex-vivo tests on porcine liver specimen. Local temperature control was monitored through a Fiber Bragg Grating, embedded in the laser probe. CE scanning was then repeated. The extent of the ablation was measured on Hematoxilin-Eosin and NADH stained slides.
Results: The diameter of the probe was too small to enable a single-shot circumferential ablation. There were no full-thickness perforations. After 50s from turning laser on, the temperature at the application site reached a plateau with minimal oscillations, and remained at mean values of 61.5±6.7 °C during both 3 and 6 minutes. Histology revealed that the mucosa ablation, at the contact areas, induced a consistent cellular necrosis (NADH-). CE scanning provided real-time images with a specific aspect of the post-ablation mucosa, including an alteration of the normal glandular structure and a general lack of enhanced imaging.
Conclusions: The local application of a circumferential laser source induced a precise and safe mucosa ablation with a long-standing increase in temperature in the CBD, in this experimental trial. However, there is a need of an adapted probe, better fitting the diameter of the CBD to enable a single-shot circumferential treatment.
Presented at the SAGES 2017 Annual Meeting in Houston, TX.
Abstract ID: 87786
Program Number: P482
Presentation Session: iPoster Session (Non CME)
Presentation Type: Poster